How to Enable APs to Return to Primary WLC

300-425 By islever Editorial Last updated Sep 29, 2026

Design high availability for APs Design high availability for controllers

Short answer

A Enable AP fallback to advise APs to return to their primary controller after it recovers.

Question

A customer with two Cisco 5520 WLCs that work as a primary and secondary had some switching issues and the primary controller lost connectivity. Immediately all APs went to discovery and joined the secondary controller. After recovering from the issue, the primary controller is online, but no APs return to it. All APs remain in the secondary controller. Which setting advises the APs to return to their primary controller?

AP fallback Correct Answer
AP multicast mode
AP heartbeat timeout
broadcast forwarding

Key Takeaways

This question tests WLC high availability and the AP fallback feature, where the common trap is confusing failover detection mechanisms with post-recovery failback behavior.

When a primary WLC fails and APs join a secondary, they will not automatically return unless specifically configured. This page establishes that AP fallback is the exact setting that allows APs to rejoin their recovered primary controller.

Common mistake: Choosing AP heartbeat timeout (C) because it relates to WLC failure detection, but it does not control the AP's behavior to revert to the primary once it recovers.

Expert Analysis

Why the Answer Is Correct

AP fallback is a feature on the Cisco WLC that, when enabled, allows an AP to rejoin its primary controller if the primary becomes available again after an outage. Without this setting enabled, the AP remains joined to the secondary controller indefinitely, even after the primary controller recovers. Therefore, configuring AP fallback directly addresses the requirement of advising APs to return to their primary controller.

Why the Other Options Are Wrong

AP multicast mode (B) configures how multicast traffic is delivered to wireless clients and has no impact on AP controller redundancy or failback behavior. AP heartbeat timeout (C) dictates how quickly an AP detects that its joined controller has failed, triggering the initial failover, but it does not control the AP's behavior to fall back to the primary once it recovers. Broadcast forwarding (D) manages how broadcast packets are handled on the WLAN and is completely irrelevant to AP-to-controller redundancy mechanisms.

Community Comment Notes

Lakshan__97 noted that without the specific feature, "the AP will stay with the secondary" and that "enabling the AP Fallback feature" changes this behavior. Farhad123 added that "AP fallback should be enabled globally", reinforcing that this is a global WLC configuration setting rather than a per-AP toggle.

Exam Strategy

For WLC high availability questions, carefully distinguish between settings that trigger a failover (like heartbeat timers) and settings that trigger a failback (like AP fallback). If the question asks about APs returning to a recovered primary, the answer is always AP fallback.

Community Votes

100%

100% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 3 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 3

Lakshan__97 👍 2 Answered A

If the primary fails, the AP will try to join the secondary until it fails. Even if the primary controller is put back into service, the AP will stay with the secondary. You can change that behavior by enabling the AP Fallback feature
Farhad123 👍 1

AP fallback should be enabled globally by the way
Farhad123 👍 1 Answered A

A is the right choice here

Reader comments & corrections

No reader corrections yet — spotted an error or have a note? Share it below.

← Back to 300-425 Study Guide